Hot-air furnace



' (No Model.)

G. B. HOPKIN. Hot Air Fur-mace.

No, 239,787. Patented April 5,1881.

. UNITED STATES PATENT OFFICE.

GEORGE E. HOPKIN, OF PHILADELPHIA, PENNSYLVANIA.

HOT-Al R FURNACE.

SPECIFICATION forming part of Letters Patent No. 239,787, dated April 5,

Application filed January 8, 1881. (No model.)

shown in the accompanying drawings, forming a part of this specification.

Figure 1 is a vertical transverse section with perspective shading. Figs. 2 and 3-the former a vertical section and the latter a perspective elevation-are enlarged views of the parts immediately connected with the feeddoor, and show what provision is made for the unequal expansion of the fire-pot and the outside casing, when, of course, this furnace is finished as a portable heater. Fig. 4 is, in vertical section, an enlarged view of the smokeflue in its way out from the furnace. It shows how the casing is clamped between flanges, also what provision I have made for combining the two sections of the same outside the furnace-casing. Fig. 5 is a detail, showing in perspective the part W and its tongues w w.

A is the tire-chamber; B, grate;- O, ashpit; D, dome of the tire-chamber, and E E E are smoke-flues from it. E is a smoke-flue from the chute to the annular smoke-flue. F is a.

passage from the (1601' G to the fire-chamber. His a blind drum over the domeof the firechamber. I I show the annular smoke-flue between the'hot-air drum and the outside hotair chamber. J is a vertical flue with a wide top, made entirely within the annular smokeflue II, so as to extend the flue K up nearly as high as the blind drum H, and thus is obtained a longer diving-draft before the exit of the smoke at K. K is the exit smokeflue from the heater. L is the dust-flue; M, the damper to the dustflue N, damper-rod 0, outlet from the ash-pit to the dust-flue; P, the sheetiron casing; Q, a wide flange upon the casting inside the casing at the door, to correspond with It, a wide flange upon the casting outside the casing at the door, so that between these two flanges, and in conjunction with two similar flanges upon the smoke-flue at the back of the furnace, space is allowed for the self-adjustment of the casin g P to meet the unequal expansion of itself with the fire-chamber A. S S are lugs. T T. U, and K K are bolts, all of the usual kind, for connecting the castings shown. V and W are two castingsparts of the smoke-flue-connectedin a novel manner to avoid the evils of screw bolts and nuts.

I have found, year by year, that the strong acids ,in the smoke-flue so affect the screwbolts, when used in this flue, that they cannot be operated. I therefore provide the casting \/V with tongues w to, with holes to match similar holes in V, and, bringing the two together, confine them by the nails 12 c, which can always he removed with ease, and thus the danger of breaking the castings, as in the former way, is removed.

I obtain by my new arrangement of the dustflue, which in this style of heater has heretofore been in the front, the following advantages: First, it delivers no dust upon any of the radiating-surfaces or within any of the smoke-flues inside the heater, so that the efficiency of the heater is not in that way obstructed; second, it keeps the dust back from the front more effectually, so that it is a greater convenience than formerly; third, it joins the smoke-flue close to its exit and just under its diving-draft, so that the heavier portions of dust will be checked at that point and fall back to the ash-pit; fourth, whatever deposits are left at K are easily reached for removal by the aid of myimproved mode of connecting the castings V and W by the nails 12 c.

I claim- 1. In combination, the converging divingflue J, the three-way casting K, and the dustflue L, substantially as and for the purpose hereinset forth.

2. The castings W and V, connected by the tongues 20 w and the nails 1; 'v, substantially as shown.

3. In combination, the dust-flue L and the exit K of the smoke-flue, composed of the cast ings W and V, connected by the tongues w w and the nails 1) 12, substantially as and for the purpose herein set forth.

GEORGE EDWARD HOPKIN. Witnesses:

J. EDWARD HURSH, J NO. W. Farmers. 

